Adducts of 1-alkenes with polyhalogenated alkanes



Patented Nov. 13, 1951 UNITEDVVSTATEJS PATENT orricc AnDUo'rs-or'ieLKENEs Qwjizrnrot HALOGENATED ALKANES United States Rubber Company, NewYork N. Y., a corporation of NewJ ersey No Drawing. Application Aprlli,1947, Serial No. 739,662

11 Claims. (orient-7593 atom is attached to the otherv carbon atom whicheonstitutedpart of said Ci-Izif=C group and sub- .iecting said adduct tohydrolyzing' conditions whereby hydrogen halides .arewelimmatedtherefrom so as to form-.compoundshaving the type formula v X-CF-Ywherein X represents 'anunsaturated organic radical and chosentrom'z-the :group consisting of organic :radicalsrand :hyiirogen.

In my co-pending application, Serials. 'No.

696,941, filed September .13; 1946,11ow11; S: Patent No. 2,468,208,there zisdisclosd the reaction tween dichlorobromomethane and: simplealiphatic olefines to form simple one ztoeone adducts which onhydrolysis yield unsaturated aldehydes; I have now found :thatrfthisreaction may be extended to include the use of otherihalogenatedhydrocarbons which contain ltwoichloririe atoms and one bromine atomattached to rthezlsame terminal carbon .atom.- .Such compounds-larenforexample, CHsCClBflLl 'di'chloro I -bromoethane), CHzCi-IzCClzBfl 1,1-dichlorolebroniopropane) CHaCH-zCI-IzCCliBrfl ,l dichloro 1bromo'butane) (CI-Ii) 2CHCH2CC12B1(1;1"" di-' chloro-d-bromo- 3-=methylbutane :CHa G-Hih- CC12Br( 1,1 -di'chloro-l -bromononane "and maybe generalized as including all those havinig tlie type formula RCClzBrwherein R-"lsa saturated' -aliphatic hydrocarbon radicaL- Thesecoiripound's' can be prepared from the corresponding-tn chloromethylalkyl compounds e' g pthose having the type formula RCCh' by reactingthe trichloromethyl compound "with a suitable quantity of an alkylbromide'ir'i the presence of a --FriedelCrai-ts catalyst such as 4aluminum chloride or "bromide; Suitable tricliloromethylf cozriprmnci'sinclude those having metype formifla' H-(CHC-Hz) M3615 which maybe-prepared from chloroform and ethylene by *the 'so-called=telomeri'zatiorif reaction disclosed iiiiBl'f-Patl581i899r 1 Otherhalogenated "hydrocarbons containing two chlorine atoms' -and onevbromine atom: attached to the same terminal carbon atom suitable foruse in my invention comprise the oneto-one adducts prepared bysubjecting to (free radical reaction conditions a reaction mixturecontaining an unsaturated organic compound containing a terminal CHz=Cgroup and dichlorodibromomethan. The resultant halogenatedihydrocarbonsmaybe generalized as being those having "the type formula wherein Rrepresents hydrogen or an organic group and :R represents hydrogen or an:alkyl ,group.

When mixtures comprising as one reactive component thereof aihalogenatedhydrocarbon containing two chlorine atoms and one bromineatomvattached :by primary valence bonds to the same terminal carbon atomand comprisingas another reactive component thereof an unsaturatedorganic compound containing a terminal CH2=C group are subjected to freeradical reactionrconditions there are formed useful bromine containinghalo organic compounds. These :come pounds contain two "chlorine atoms:attachedmto one carbon atom and -.a bromine atom attached to adifferent carbon atom. .7

The aforementioned reactionrmixture is subjected to: freeuradical.;rea;ctiorr conditions either by irradiating the mixture :with .actiniclight or by heating the reaction mixture with ;a-sub. stance which iscapable .01 acting as :a catalyst for ethylene polymerization .but which.is ineffective as a catalystuforthe ,Friedel-Craftsreaction; Suitablecatalysts are enumerated UJ-Sl P.- 2;402,1'3 7. Of these catalystsIV-prefer to use the di'acyl :peroxi des :such as. .for example,diacetyl"peroxideeand dibenzoyllperoxide; diacyl peroxides are employedas the catalysts, the temperature towhich the reaction mixture is heatedshould' be: suflicient :to decompose .the peroxide. Ingeneral;temperatures between room temperature (20 C.) and about 150 C. arepreferred. I t

It is preferred to have in 'the'reaction mixture somewhat more than onemolecular weight. .of the halogenated hydrocarbon tor each molecularweightof the-unsaturatedorganic compound. In

or more molecular weights of thehalogenated appreciable amount of thedesired adduct I mean.

any amount of the adduct which is separable from the reaction mix by theusual chemical means such as distillation or extraction.

organic compounds and the halogenatedhydrocarbons may be separated fromthe other components present in the reaction mixture by the methylbutanewhich can be hydrolyzed to #3,,9- dimethylacrolein.

In the same type of reaction, vinyl acetate and bromodichloromethanegive 1-bromo-3,3-dichloropropyl acetate. Derivatives offifi-dichloropropionaldehyde are prepared directly from this eszter;Propyleneiand bromodichloromethane give 1,1-dichloro-3-bromo-butanewhich gives crotonaldehyde upon hydrolysis.

The stepwise reaction of one mole of dibromo- Ldichloromethanewith twomoles of olefin yields halides which can be hydrolyzed to substitutedThe one-to-one adducts of the unsaturated divinyl ketones.

These adducts are convertible by hydrolysis into.

either unsaturated ketones or aldehydes. The adducts are thusdistinguishedfrom the adducts of. either chloroform, carbontetrachloride, or trichlorobromomethane with olefinic compounds sincethese latter adducts are converted by hydrolysis into acids. a

, Dichlorobromomethane adds to unsaturated organic compounds containinga terminal group, and in particular to-acyclic l-alkene hydrocarbons toform adducts-which are convertible by hydrolysis to unsaturatedaldehydes. Halogenated aliphatic hydrocarbons containing at least twocarbon atoms and in which two chlorine atoms and one bromine atom areattached to the same carbon atom add to the same type of unsaturatedorganic compounds to form adducts which are hydrolyzable to-unsaturatedketones.

The addition under free radical reaction con-.

ditions of dichlorodibromomethane to olefines is unique as compared tothe behavior of other tetrahalomethanes in" such reactions.Dichlorodibromomethane adds to olefines to form one-tone adducts whichcontain two chlorine atoms and one bromine atom attached to the samecarbon-atom and these adducts may be separated from the reaction mixtureand caused to react with an olefin which need not be the same olefin aswas used to react with the-dichlorodibromomethane. By this reactionthere will be produced adducts which are hydrolyzable to unsaturatedketones. l.

Dibromodichloromethane also adds to olefines to form two-to-one adducts,that is to say, compounds containing inchemical combination the atomsfrom two molecules of olefin and one of dibromodichloromethane. Thesetwo-to-one adducts are distinguished from the so-called telomersobtained by the reaction between olefines and other tetrahalomethanes inthat my two-toone adducts are hydrolyzable to unsaturated ketoneswhereas the so-called telomers of carbon tetrachloride and chloroformare hydrolyzed to acids.

For a more complete understanding of the methods of carrying out myinvention and the results obtained thereby, reference is made to thefollowing examples. V

When a mixture of bromodichloromethane, octene-l and a catalytic amountof diacetyl peroxide is heated at 70 C. for'six hours,1,1-dichloro-B-bromononane is obtained in 80% yield. Hydrolysis of thishalide yields 2-nonenal. Similarly, the reaction of bromodichloromethanewith isobutene gives 1,1 -.-dichloro 3 bromo-3- oBno1+ menace.

usual chemical processes as, for example, by. dis-f" tillation underatmospheric or reduced pressure.

Light or diacyl peroxide (l-2 mole per cent) CHzCHBr CHsC 011131 Y IDiacyl peroxide CHQCHBICHqCChBI CHiCH=CHz I r (1-2 mole per cent)CHaCHBrCHzC CI2CH2CHBICH3 Thelightor peroxide-initiated addition ofdibromodichloromethane to propylene yields 1,1-dichloro-1,3-dibromobutane (I). Further reaction of (I) with propylenegiVes 2,6-dibromo-4A- dichloroheptane. 2,6-dibromo-lA-dichlorododecaneis produced by the reaction of (I) with octene-l. v EXAMPLE I Thereaction of bromodichloromethane with-propylene in the presence ofdiacetyl peroxide A solution of diacetyl peroxide (2.2 gr.) inbromodichloromethane .(167.4 gr. B. P. 88 C.; n =1.4962) is placed inthe stainless steel bomb of a modified Parr hydrogenation apparatus.After evacuating and flushing the system several times with propylene,the reaction mixture is heated to 60 C. under .apropylene pressure of 45pounds. These conditions are maintained for 12 hours, and propylene isslowly consumed.

The reaction mixture is distilled through an 8 inch Vigreux column.After unreacted bromodicloromethane (B. P., 25-28 C. at 30 mm.; 115 gr.)is removed,- 1,1-dichloro-3-bromobutane (B. P. 76 at 30'mm.; 33.3 gr.; n=1.4912) distills.

Anal. calcd for C4H7BIC12: Silver equivalent, 68.3. Found, 68.5.

A high-boiling residue-(11.3 gr.) remains in the distilling flask.

Proof of stracture of 1,i-dichloro-3-bromobutane Sodium (19-gr.; 0.84mole) is added in small pieces to ethylene glycol (250 ml.) held at atemperature of C. After all of the sodium has disappeared, thebromodichloromethane-propyleneaddition product (30 gr.; 0.145 mole) isadded over a period of 20 minutes with stirring. The temperature of thereaction mixture is maintained at, C..for5 hours. During this time, aheavy white precipitate appears.

The reaction mixture is acidified with dilute hydrochloric acid, and theresulting solution is distilled under vacuum. An aqueous solution (73ml.) distills. "An aliquot of this solution (5 ml.) is treated with2,4-dim'trophenyl hydrazine reagent. The crimson precipitate which formsis shown tobe the 2,4-dinitrophenyl hydrazone of crotonaldehyde (M. P.189 C., after recrystallization from a benzene-ligroin mixture; mixed M.P. with authentic sample, 189 0.). The

The. reaction of bromodichtoromethafne with. octene-I in the presence ofdiacetyl peroxide.

solution ofdiacetyl" peroxide (524 gr.) in liromodichloromethane (30gr.) is" dropped" over asperiod'of 'two hours into a solutionoff'octene-l (56 gr.)- in bromodichloromethane (387 gr held atf75-' C.To complete the reactiomthe reaction mixture is maintained at 75 C; forthree more hours; a

"After" unreacted bromodichloromethane has. been removed bydistillation, a fraction"- (1:1216' gr; n ?=1.4842-) distills atflGS" C.at 0.03 mm. substance is showrr to be l,l-dichlo ro-'3-" bromononane.(Yield, 82% of-theory.)

Anal. calcd for CsHrzBrClz; Agequivalent; 92;: Found, 91.7. v

A high-boiling residue- (1-7.5 g-r-.) is left in the stillpot. Thisresidue probably contains higher polymers with more than one octene unitper bromodichloromethane.

The. bromodichloromethane-octene-l addition product1-(96.0 gr.; 0.35mole) is-slowlyv dropped into; a: vigorously stirred solution of sodiumethylate; (prepared by the reaction of sodium, 46 gr., with absoluteethanol, 500 ml.). Heat is evolved. during the addition, and a heavywhite solid is precipitated... Aftersthe addition iscom plete, thereaction mixture is heated under reflux for ten hours.

After the reaction mixture has cooled, precipitated salts are removed ona filter, and the filtrate is acidified with acetic acid: The mixture isthen warmed to 50 C., and maintained at this temperature for two hours.After cooling, the mixture is added to water.,(l"liter). The oilylayerwhich separates is takenupin ligroin', (35 C.), and the water layeris extracted'with three additional portions of ligroin (300 ml. each).The combined extract iswashed with water, sodium carbonate solution(5%), and then again with water. It is dried over anhydrous sodiumsulfate. 7

After the'ligroin has been removed from the extract, abrown oil remainswhich is distilled at re.- duced pressure. The first fractions (11.0gr.; B; P. 30+51-C. at'0.2 mm.) are tcomposedof halogencontaining;substances whichgare not identified; Then, 2-nonena1 (29.2'gr3; B. P.55-57. C. at.0.2 nun; n =1.4499;,yield, 60%; of theory),.distills Thissubstance is converted to. its 2,4-.-.dinitro.-.-. phenyl hydrazone (M.P: 124? C.; mixed M. P... with: authentic sample, 1245-125" C.). ;2'=nonenal (B, P. 5658'C. at 0.2 mm.; ,n ==:1.4 502); wasmade for comparisonby the method of Scan.- Ian; and Swern. (J. Am. Chem. 800., 2.2 9(.1940) EXAMPLE .3

Reaction of bromodichloromethane with iso butylene in the presence ofdiacetylperoxide.

A solution of diacetylperoxide (2 gr. in bromodichloromethane (100 gr.)is treatedkwith isob'utylene in the Parr apparatus usinjgthe-conditionsalready descrihed for the bromodichloromethane-propylene reaction. a r 3The reaction mixture is distilledthrough a small ivigreux column. Afterunreactedbromodichlorom'ethane (B. P. ac -22s c: at 32. mm. 54.81;

gr.) is removed, 1,1-dichloro=3:ebromo*-B-methyL butane (34.0: gr..;131.121.7548? 0.. at. 12,,mm.; n =1.4960) distills.

Anal. calcd for CsHaBrClzt Ag equivalent, 73.3. Found, 72.0.

A small residue (3.4" gr.) remains in the distilling flask.

Proof of the stractareof 1,1-dichZoro-3-bromo- 3-methylbatane Thebromodichloromethane-isobutylene addition-product (14 gr.) isslowlyiadded' to a strongly stirred. sodium ethylate solution (made bydissolving sodium, 9 gr., in 200ml. of absolute ethanol). Avigorousreaction which heats the reaction. mixture to .theboilingv pointensues, and awhite precipitate appears. Thereaction mireturesis heatedunder refiuxfor 12hours, and thenallowed to cool.

Precipitated salt (9.5 gr.) are separated upon a Buchner filter, and thefiltrate is distilled at reduced pressure through a l2-p1atefractionating. column to. remove the ethanol. When the volume of theundistilled mixturereaches-about ml., ligroin (35 C.; 200ml.) is added.The ligroin solution is washed with water, dilute hydrochloric acid,andagain with water. It'is dried over anhydrous sodium sulfate.

The ligroin solution is distilled. After: the ligroin. has been-removed,abrown oil remains. It distills from C. to '70 C. at 50 mm. pressure (6.gr.; n :l.4446). When this. oil istreated with.2,4-dinitrophenylhydrazine reagent, dark red crystals form. These areshownto be the 2, l-dinitropheny1 hydrazone of. p,c-dimethylacrolein (M.P. 178 C., after. three recrystallizations. from ethyl acetate; mixed M.P. with authentic sample, 178-178.5 0.). For comparisonv purposes,p,c-dimethylacroleinwas made by the method of Fischer, Ertel andLowenberg. (Ben, 64B, .30 (1931).)

EXAMPLE 4' The reaction of vinyl acetate with bromodichloromethane inthe presence of diacetyl peroxide A solution of diacetyl peroxide (2.5gr.) in

- bromodichloromethane (30 gr.) is added in increments during a periodof 4 hours to a solution containing vinyl acetate (50 gr.) andbromodichloromethane (375 gr.) the temperature being maintained at 65 C.The reaction mixture is maintained at this temperature for another 2hours after the addition is complete.

After unreacted vinyl acetate and bromodi; chloromethane have beendistilled (B. P. 0-48 G'. at.100 mm.), an 'oily' product remains. Highvacuum distillation of this oil yields l-bromo-3; S-dichloropropylacetate (B. P. 58 C. at 0.2 mm.; 60 gr.; n =l.4782). The yield isquantitative on the basis of the vinyl acetate consumedin the reaction.

Anal. calcd for C5I-I'102BIC12: Ag equivalent, 83.3. Found, 82.0.

' A residue (16.5 gr.) remained in the distilling flask.

When this addition product (1 gr.) is added to-a solution of2,4-dinitrophenyl hydrazine (1.5 gr.)in ethanol :35 ml.) containingconcentratedhydrochloric acid (21111.), orange needlelikecrystals (1.5gr.) precipitate. This product gives the correct chlorine analysisforthe 2,45 dihitrophenyl hydrazone of pfi-dichloropropion EXAMPLE Thereaction of dibromodichloromethane with propylene in the lightDibromodichloromethane (300 gr.; B. P. 66-67 C. at 95 mm.; n =1.5509) isplaced in a reaction vessel illuminated internally by a mercury-neoncoil. Propylene is slowly bubbled through the solvent for a period offifty hours. The heat from the light maintains the reaction mixture at50 C.

.The reaction mixture is distilled through a short Vigreux column. Afterunreacted dibromodichloromethane has been removed,1,1-dichloro-1,3-dibromobutane (B. P. 47-48 C. at 0.2 mm.; n =1.5370;145.5 gr.) distills. A residue (4.5 gr.) remains in the distillingflask.

This dibromodichloromethane-propylene addition product is also preparedby carrying out the reaction in the presence of diacetyl peroxide in theParr apparatus.

EXAlVIPLE 6 The reaction of 1,1-dichZoro-1,3-dibromobutane withpropylene in the presence of diacetyl peroxide A solution of diacetylperoxide (2 gr.) in 1,3-

dibromo-1,1-dichlorobutane (120.0 gr.) is shaken with propylene (40pounds pressure) for hours at 80 C. During this time, propylene (0.2mole) is consumed.

After unreacted solvent has been removed from the reaction mixture, afraction (B. P. 76-80 C. at 0.05 mm.; 38.5 gr.; n =1.4282) distillswhich is probably 2,6-dibromo-4,4dichloroheptane.

Anal. calcd for C7H12BI2C12: Ag equivalent, 81.7. M01. wt., 327.

Found: Ag equivalent, 82.0. Mo1.,wt., 321.

EXAMPLE 7 The reaction of 1,1-dichZoro-1,3-dibromobutane with octene-Iin the presence of diacetyl peroxide A solution of diacetyl peroxide (2gr.) in 1,1-

dichloro-1,3-dibromobutane (285 gr.; 0.69 mole) and octene-l (20.0 gr.;0.18 mole) is held at 70 for 10 hours, then at 100 C. for 3 hours.

The reaction mixture is then distilled. First, octene-l (6.0 gr.; 32-40C. at 43 mm.) was recovered, and then unreacted solvent (206.0 gr.; 0.52mole; B. P. 62-67 C. at 1 mm.) distilled. The residue is distilled in amolecular still. Three fractions having the same refractive index (n=1.5119) distill. This'substance is probably2,6-dibromo-4,4-dichlorododecane (41.2 gr.; conversion 60%). The yieldis quantitative on the basis of the octene consumed in the reaction.

Anal. calcd for C12H22C12B12: Ag equivalent, 99.2. M01. wt. 397.

Found, Ag equivalent, 99.5. Mol wt. 394.

It can thus be seen that the freeradical catalyzed addition to olefinesand substituted olefines of halogenated hydrocarbons containing twochlorine atoms and at least one bromine atom attached to the same carbonatom is a novel and useful synthetic method yielding many novel andhitherto unknown halogenated bromine containing organic compounds whichare hydrolyzable to form a large variety of useful organic carbonylcompounds such as unsaturated hydes and ketones.

Thus my invention provides not only a method for making new and usefulhalogenated organic compounds but also provides a new and useful methodfor producing unsaturated ketones, aldehydes and derivatives thereof.

These unsaturated ketones and aldehydes may be employed as chemicalintermediates in the production of a variety of products including dyes,pharmaceuticals, perfumes and plastics.

Since many variations may be made in the specific methods disclosedherein without departing from the spirit of my invention, refer: ence ismade to the appended claims for a delineation of the true scope of myinvention.

Having thus described my invention, what I claim and desire to protectby Letters Patent is:

1. Process of producing useful bromine-containing chlorinated organiccompounds which comprises subjecting a reaction mixture containing asone reactive component a l-alkene and containing as another reactivecomponent a halogenated alkane containing only two chlorine atoms andone bromide atom attached to the same carbon atom which in turn islinked to a radical from the class consisting of hydrogen. alkyl,bromine and bromalkyl, to reaction in the presence of a reactioninitiator from the class consisting of free radicals formed by theaction on the mixture of actinic light, and free radicals aldeformed bythe action on the mix of a diacyl peroxide.

2. A process as in claim 1 wherein the halogenated alkane isdichlorobromomethane.

3. A process as in claim 1 wherein the halogenated alkane has the typeformula R being an alkyl radical.

4. A process as in claim 1 wherein the halogenated alkane has the typeformula R being an alkyl radical.

5. Process of producing organic carbonyl compounds which comprisessubjecting a reaction mixture containing as one reactive component al-alkene and containing as another reactive component a halogenatedalkane containing only two chlorine atoms and one bromine atom attachedto the same carbon atom which in turn is linked to a radical from theclass consisting of hydrogen, alkyl, bromine and bromalkyl, to reactionin the presence of a reaction initiator from the class consisting offree radicals formed by the action on the mixture of actinic light, andfree radicals formed by the action on the mix of a diacyl peroxide, andforming an appreciable amount of the one-to-one adduct of the l-alkeneand the halogenated alkane, separating said adduct from the othercomponents of the reaction mixture, and subjecting said adduct todehydrobrominating and hydrolyzing conditions.

. 6. Process of producing aldehydes which comprises subjecting areaction mixture containing as one reactive component a l-alkene andcontaining as another reactive component dichlorobromomethane, toreaction in the presence of a reaction initiator from the classconsisting of free radicals formed by the action on the mixture ofactinic light, and free radicals formed by the action on the mix of adiacyl peroxide, and forming an appreciable amount of the oneto-oneadduct of said l-alkene and dichlorobromomethane, separating said adductfrom other hydrolyzable components of the reaction mixture, andsubjecting said adduct to dehydrobrominating and hydrolyzing conditions.

7. Process of producing ketones which comprises subjecting a reactionmixture containing as one reactive component a l-alkene and containingas another reactive component a halogenated alkane having the typeformula 01 li-o ci where A represents a bromalkyl radical, to reactionin the presence of a reaction initiator from the class consisting offree radicals formed by the action on the mixture of actinic light, andfree radicals formed by the action on the mix of a diacyl peroxide, andforming an ap preciable quantity of the one-to-one adduct having theformula A--CCl-2B where A and B each represent bromoalkyl, separatingsaid adduct from the other components of the reaction mixture, andsubjecting said adduct to dehydrobroone adducts of acyclic l-alkenehydrocarbons with saturated halogenated hydrocarbons having the formulaACBrClz, where A represents bromoalkyl, which adducts contain at least 4carbon atoms and have the general formula ACC12B, where A and B eachrepresent bromoalkyl, and are characterized by being convertible bydehydrobromination and hydrolysis to unsaturated ketones.

10. A process as in claim 1 wherein the halogenated alkane isdichlorodibromomethane.

11. A process as in claim 1 wherein the halogenated hydrocarbon has thetype formula where A is bromoalkyl.

MORRIS S. KHARASCH.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,322,258 Strosacker et a1. June22, 1943 2,359,459 Anderson et al Oct. 3, 1944 2,398,430 Joyce Apr. 16,1946 2,410,541 Joyce Nov. 5, 1946 FOREIGN PATENTS Number Country Date581,899 Great Britain Oct. 29, 1946 OTHER REFERENCES Kharasch et al.,Science, vol. 102, No. 2640, page 128, Aug. 3, 1945.

Beilstein, Handbuch der Organischen Chemie," vol. I, pages 90, 111, 121,Berlin, 1918.

1. PROCESS OF PRODUCING USEFUL BROMINE-CONTAINING CHLORINATED ORGANICCOMPOUNDS WHICH COMPRISES SUBJECTING A REACTION MIXTURE CONTAINING ASONE REACTIVE COMPONENT A 1-ALKENE AND CONTAINING AS ANOTHER REACTIVECOMPONENT A HALOGENATED ALKANE CONTAINING ONLY TWO CHLORINE ATOMS ANDONE BROMIDE ATOM ATTACHED TO THE SAME CARBON ATOM WHICH IN TURN ISLINKED TO A RADICAL FROM THE CLASS CONSISTING OF HYDROGEN ALKYL, BROMINEAND BROMALKYL, TO REACTION IN THE PRESENCE OF A REACTION INITIATOR FROMTHE CLASS CONSISTING OF FREE RADICALS FORMED BY THE ACTION ON THEMIXTURE OFTINIC LIGHT, AND FREE RADICALS FORMED BY THE ACTION ON THE MIXOF A DIACYL PEROXIDE.